I do think there was a distinct period 10-15 years ago where, particularly when trying to break into the startup scene as a rookie developer coming from a non-CS education background, the blog was a useful place to write about technology just to show you were actually connected to "the scene" somehow even though you had limited professional experience. Somewhere out there I still have a neglected personal blog with posts from those days where I was hacking open source firmware onto a WiMAX receiver so I could use it as a router, sharing source for some audio processing effects plugins I wrote in college courses, things like that... cool stuff for a college kid, but not what I spend time doing now years into my career. At this point my credibility is from my professional work.

Of course, that's exactly why it eventually became standard for every aspiring rookie developer to have a blog; and eventually these just turned into straight-up programming TIL blogs as more and more people who weren't ever tech hobbyists entered the field. The signal quality diminished, and in the modern world of ML-assisted ATS resume screening it may not even be a signal at all.

Basically, "building a brand" as a certain kind of technologist had value when relatively few people were doing it. Now I think its very fair to question as a tool for getting hired.

Anybody who writes because they like writing should certainly continue to do so!